Generally, a vehicle is equipped with at least one safety device for user convenience and safety.
Particularly, in case of a car accident, various applications are used to activate the safety device for the safety of a passenger by using a distance from the safety device to the passenger such as a driver.
For example, when an airbag is deployed due to the car accident, inflation time of the airbag is increased if a distance between the airbag and the passenger is long, and the inflation time of the airbag is decreased if the distance between the airbag and the passenger is short. Thus the airbag is deployed according to the distance between the airbag and the passenger, thereby preventing a secondary injury caused by the collision.
In addition, by using the distance to the driver, who is one of the passengers of the vehicle, when an abnormal situation such as bending-over of the driver is detected, an alarm is sounded, thereby preventing accidents due to distraction.
The distance to the passenger used for performing the operation of the safety devices as such is measured using various sensors.
However, when the distance to the passenger is measured using the sensors, it is difficult to acquire accurate sensor information adequate to various positions of the passenger and changing driving environments, and the various sensors for distance measurement increase the cost.
Accordingly, the inventors of the present disclosure propose a method for measuring the body position of the passenger at a lower cost than conventional methods.